关键词: 长沙, 冷暖冬, 气候特征, 冬季环流特征指数

Abstract: Based on the meteorological data in Changsha from 1971 to 2007,the climate resources in winter were statistically analyzed,to analyze the adverse impacts of winter warming up on agricultural production and make use of winter climate resources. The results showed that the winter temperature increased significantly and the appearances of warming winter was more and more frequent since 1990s. The obvious increase of the average minimum temperature in winter led to decrease of the frost damage and change of the cropping layout,but the variability of the extreme minimum temperature was still great. The anti-freezing measures were needed in the face of strong cooling or cold wave. The average temperature of January in the recent six years was close to that of February in 1970s,which was propitious to the yield of out-of-season vegetables and other crops. Generally warmer winter was also dry,so effective insecticide treatments and timely irrigation should be carried out during seeding for the maintenance of the soil moisture. In the following year of warm winter,the temperature of March and April was often higher than that of the conventional year,which provided favorable conditions for the seeding of early rice and cotton. Finally,it also revealed that some characteristic indexes of the winter circulation could be as indicators in determining the occurrence of a warm winter.

Key words: Changsha, Changsha, Cold and warm winter, Climate characteristics, Index of winter atmospheric circulation feature